Project summary/Abstract The burden of functional limitations (restrictions in basic physical actions) and disability (problems with daily activities and life participation) may be more common in middle-aged US adults than previously recognized. However, studies of middle-age populations have not typically included functional assessments. The Coronary Artery Risk Development in Young Adults (CARDIA) study provides a unique opportunity to study functional status in a diverse, aging cohort. The Year 35 in-person exam is scheduled for 2020 and 2021, at which time, participants will be 53 to 65 years old. We propose a CARDIA ancillary study to obtain measures of function by self-report and physical performance to be paired with the existing data collected from early adulthood through middle age to address the following aims: 1. To quantify the burden of functional limitations and disability in middle age and assess the degree to which this can be attributed to the accumulation of chronic conditions, 2. To assess domains of functional limitations and disability captured by physical performance versus self-report, 3. To identify health-related risk factors in early adulthood for functional limitations and disability in middle-age, 4. To identify health-related, socioeconomic, and psychosocial factors that contribute to between- and within- race differences in functional limitations and disability among middle-aged adults. We will add measures of physical performance (fast and usual gait speed, single leg balance, timed chair stands, 6-minute walk test, and grip strength) to the CARDIA Year 35 exam (projected N=3,270; 1,563 black, 1,707 white). Also, self- reported functional limitations (Patient-Reported Outcomes Measurement Information System [PROMIS] Physical Function Short Form 20a) and disability measures (basic and instrumental activities of daily living) will be added to the Year 35 exam and annual telephone calls (1 call prior to and 2 after the Year 35 exam). As studies of younger populations have not often included functional assessments, the conceptualization, measurement approaches, risk factors, and implications of functional limitations and disability are poorly understood. Filling this knowledge gap by adding appropriate functional measures to an ongoing population based cohort, that represents the next wave of aging black and white adults will lead to new approaches to prevent functional decline and improve population health.